The present invention relates to a semiconductor device and a method of manufacturing the semiconductor device, in particular to the semiconductor device and the method of manufacturing the semiconductor device in which a plurality of semiconductor chips are stacked with high density.
As regards mounting of a semiconductor package and a semiconductor chip, it is important that the semiconductor package and the semiconductor chip are mounted in small area and capacity, but with high density, and at a low cost. For this purpose, semiconductor chips are progressively miniaturized, and Multi-Chip Module (hereunder called “MCM”) method, as will later be described more in detail, is used as a method of mounting those semiconductor chips. In the MCM method, a plurality of semiconductor chips are mounted on a ceramic wiring substrate, silicon wiring substrate, and a printed wiring substrate by wire bonding or flip-chip mounting. Moreover, Multi-Chip Package (MCP) method is used as another conventional method of mounting a plurality of semiconductor chips, also as will later be described more in detail. In the MCP method, a plurality of semiconductor chips having different sizes from each other are stacked three-dimensionally and electrically connected to each other by wire bonding.
It is difficult for some different function devices, of which manufacturing processes are different from each other, to be integrated in a semiconductor chip, because of cost and technical problems. A package capable of compositing different function devices into a system, such as MCM, MCP or the like is used therefor. However, the package such as MCM or MCP has, for example, the following problems.
Namely, it becomes difficult to make the MCM package small in size and with high density. Further, manufacturing cost of the MCM package becomes high. Further, delay of electric signals is inevitably caused to occur, since wiring length becomes long in the MCM package. It is therefore difficult to obtain a desirable characteristic of high-speed operation.
On the other hand, the MCP package becomes large in thickness. As a result, the MCP package is not always suitable to be manufactured with high density. In addition, total bonding wires become so long. As a result, delay of operation speed is inevitably caused to occur due to parasitic capacitance or wiring resistance.